Fix error when decoding null values using manifest_decode() (#2461)

Author: jrhouston

.changelog/2461.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+`manifest_decode()`: fix handling of manifests containing null values
+```

internal/framework/provider/functions/decode.go

@@ -87,6 +87,8 @@ func decodeSequence(ctx context.Context, s []any) (attr.Value, diag.Diagnostics)
 
 func decodeScalar(ctx context.Context, m any) (value attr.Value, diags diag.Diagnostics) {
 	switch v := m.(type) {
+	case nil:
+		value = types.DynamicNull()
 	case float64:
 		value = types.NumberValue(big.NewFloat(float64(v)))
 	case bool:

internal/framework/provider/functions/manifest_decode_multi_test.go

@@ -35,11 +35,13 @@ func TestManifestDecodeMulti(t *testing.T) {
 							}),
 							"kind": knownvalue.StringExact("ConfigMap"),
 							"metadata": knownvalue.ObjectExact(map[string]knownvalue.Check{
+								"annotations": knownvalue.Null(),
 								"labels": knownvalue.ObjectExact(map[string]knownvalue.Check{
 									"test": knownvalue.StringExact("test---label"),
 								}),
 								"name": knownvalue.StringExact("test-configmap"),
 							}),
+							"status": knownvalue.Null(),
 						}),
 					})),
 				},

internal/framework/provider/functions/manifest_decode_test.go

@@ -33,11 +33,13 @@ func TestManifestDecode(t *testing.T) {
 						}),
 						"kind": knownvalue.StringExact("ConfigMap"),
 						"metadata": knownvalue.ObjectExact(map[string]knownvalue.Check{
+							"annotations": knownvalue.Null(),
 							"labels": knownvalue.ObjectExact(map[string]knownvalue.Check{
 								"test": knownvalue.StringExact("test---label"),
 							}),
 							"name": knownvalue.StringExact("test-configmap"),
 						}),
+						"status": knownvalue.Null(),
 					})),
 				},
 			},

internal/framework/provider/functions/testdata/decode_single.yaml

@@ -6,9 +6,11 @@ apiVersion: v1
 kind: ConfigMap
 metadata:
   name: test-configmap
+  annotations: null
   labels:
     test: "test---label"
 data:
   configfile: |
     ---
     test: document
+status: